213721154 has 4 divisors (see below), whose sum is σ = 320581734. Its totient is φ = 106860576.

The previous prime is 213721153. The next prime is 213721159. The reversal of 213721154 is 451127312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 167003929 + 46717225 = 12923^2 + 6835^2 .

It is not an unprimeable number, because it can be changed into a prime (213721153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 53430287 + ... + 53430290.

Almost surely, 2^213721154 is an apocalyptic number.

213721154 is a deficient number, since it is larger than the sum of its proper divisors (106860580).

213721154 is a wasteful number, since it uses less digits than its factorization.

213721154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106860579.

The product of its digits is 1680, while the sum is 26.

The square root of 213721154 is about 14619.2049715434. The cubic root of 213721154 is about 597.8824931398.

Adding to 213721154 its reverse (451127312), we get a palindrome (664848466).

The spelling of 213721154 in words is "two hundred thirteen million, seven hundred twenty-one thousand, one hundred fifty-four".